Diamond



FIG. 1 is a bottom plan view of a diamond showing my new design;

FIG. 2 is a side elevational view; and,

FIG. 3 is a top plan view, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design.

The portions of the stone shown in broken lines in FIGS. 1-5 are for environmental purposes only and form no part of the claimed design. 

The ornamental design for a diamond, shown and described in the drawings. 